Talk abstract details

In late Main Sequence solar-like pulsators, the coupling between the p-mode cavity and the g-mode cavity is strong for modes of low degree \ell. In a previous work (Deheuvels and Michel 2009), we have shown that in this case, an avoided crossing affects more than two modes, and induces a characteristic and easily identifiable distortion of the ridge of degree \ell in the \'echelle diagram. This distortion is linked to the size of the evanescent zone between the two cavities.

It is well known that the frequency at which the avoided crossing occurs is sensitive to the amount of overshooting at the boundary of the core (Dziembowski and Pamyatnykh 1991). The distortion in the ridge provides information on the profile of the V\"ais\"al\"a frequency, and therefore on the gradient of chemical composition in the central regions. We here investigate on the possibility of complementarily using these two features to obtain a quantitative diagnostic on the internal \mu-gradient and on the processes responsible for the extension of the mixed zone associated to the convective core. Our results are applied to the case of solar-like CoRoT target HD 49385, for which a distortion of the \ell=1 ridge, due to the presence of an avoided crossing, has been detected.